The bullet curtain or barrage subtitles is a technology to display user comments which drift on a screen. At present, the bullet curtain has been more and more widely used. For example, the bullet curtain may be displayed on the screen while a video is being played; the bullet curtain may be added into some live matches or variety shows; and the bullet curtain may also be offered when some cinemas show films. Existing bullet curtains are mainly applied in 2D plane display areas. During playback of the video, a number of bullet curtains sent by other users may pop up from a right side of the screen and slide to the left. In case of playback of a live video, the bullet curtains may be sent by other users in real time; and in case of playback of a recorded video, the bullet curtains may be sent by other users in real time, or may be sent by other users when they have been playing to a current time point in the video.